High end Cables not important for certain electronics?

@almarg Thanks for the info an link. Maybe I can live with my existing lower end XLR's. I need to research what you have posted and see how it applies to what I am considering.

Not allways true even in a fully balanced system .
i owned a audio store for 10 years in Europe and had many top 
electronics top quality Balanced interconnects trumped the lesser models every time , maybe with what some would call diminishing 
returns for example the $2k cables were roughly 5% + better then a similar cables at $1k ,this applied to Every one of at least 4 well
known brands. Noise floor even lower and resolution and separation was just more defined. Equipment too will vary to some  extent I used  world class Amplifiers and preamps , not fake balanced, like most. Outthere . That have xlr,then wired to same rca grid. True balanced has Transformers input to output.and yes I used Solid state as well as vacuum tube. 

But it says right here in the manual.....

High end cables are unnecessary. End of the story.Check out Ethan Winer's null test.

As a former professional recording engineer, I can attest that cable is every bit as variable on balanced connections as unbalanced.

In some situations, cables make next to zero difference and others, large.

The only constant is YMMV